General guide to sunglass categories and their uses
30th August 2024
We are often asked about the Category of lenses used for sunglasses and eyewear – what do they mean. The categories range from 0 to 4 with each one covering a range of VLT (visible light transmission – basically how much light the lens lets through).
The vast majority of sunglasses are Category 3 and these have a VLT range of 8 – 17%. Blocking over 80% of light coming through makes them suitable for use in strong sun and for everyday recreational sunglasses.
Lighter lenses with high VLT (Cat. 0 & Cat. 1) will be used in low, dull and poor light conditions and for specific sports like clay target shooting.
Category 4 lenses are very dark, letting 8% or less of light – they are typically used at high altitude where glare can be intense with a high risk of photokeratitis (snow blindness). They are also suitable for eyes that are sensitive to light, a fairly common condition known as Photophobia. As the chart shows they should never be used for driving – they are too dark and therefore potentially dangerous. View our range of Category 4 sunglasses.
Continue reading
The benefits of wrap-around sunglasses
Enhanced UV protection Full wrap, sports style sunglasses keep out the elements like sand, dust, grit and wind from getting into your eyes - potentially painful and dangerous. Importantly, unlike "normal" leisure style sunglasses they also stop glare and UVR...
Beware of the dangers of ‘street’ sunglasses
On your overseas holiday this summer you'll no doubt come across beach, street and market stall vendors selling sunglasses. Very rarely is it worth buying these, however cheap they are. Chances are the lenses will be poor quality with distortion...